Analysis Of Seismic Behavior Of Long Span Concrete-Filled Steel Tubular Arch Bridges

Adapted to the developing direction towards long span, high storey, heavy load of modern projects, concrete-filled steel tubular (CFST) structures have been widely used in industrial work-shops, high and super-high buildings, arch bridges and underground buildings. It has been an important branch of Structural Engineering Science. With the high bearing capacity, strong spanning ability, convenience of construction and good economic benefits, CFST arch bridges develop rapidly in China. As China is a country with earthquakes often-occurred, under the present conditions that CFST arch bridges have been widely used, studying on the seismic behavior is very necessary and urgent. Now the earthquake-resistant theoretical research on CFST arch bridges is in the beginning. Systematic design program has not been constructed and no specialized design specification exists. The knowledge about CFST arch bridges' seismic behavior is very limited. Therefore, studying on the seismic behavior of CFST arch bridges, constructing the consummate dynamic analysis methods and determining scientific earthquake-resistant design principles are very urgent.To research Seismic Behavior on CFST arch bridges and change the condition of theoretical research below the project practice, this article around its basic dynamic characteristics and 3D-spatial elastic-plastic time history reactions, main works done are as follows.1. Carrying out the dynamic characteristics analysis of CFST arch bridges. Use common finite element program-ANSYS to establish model of existed CFST arch bridges, calculator its dynamic characteristics. By the compare of gathered dynamic characteristics of several CFST arch bridges in practice, laying a foundation for further research on the CFST arch bridges' dynamic characteristics.2. Discussing the seismic spectrum analysis of a CFST arch bridge. With geographic conditions of the bridge and available specification of Earthquake Resistant Design for Highway engineering, the thesis created the seismic spectrum curve of the spot. On the basis of the curve, the displacement and force are introduced under theseismic effect.3. With the method of 3D-spatial time history analysis, the thesis analyzed the seismic behavior of some CFST arch bridge in practical project of high-intensive district, and focusing on the influence of traveling wave effect to this CFST arch bridge. Providing and perfecting the basic materials for determination of seismic design concept and construction of seismic design systems in CFST arch bridges.4. According to resists earthquakes the analysis result to put forward some valuable project proposals.